1. Field of the Invention
The present invention relates to surgical instrument for minimally invasive surgery.
2. Discussion of the Prior Art
From DE 100 36 108, a surgical instrument of this generic type is known. It substantially consists of a tube shaft at the one proximal end of which an instrument handle is arranged for the operation of an instrument head disposed at the opposed distal end of the tube shaft via gear trains. The instrument head can be pivoted and/or inclined with respect to the tube shaft and, moreover, holds an effector rotatably supported in the instrument head in the form of a type of forceps or tongs one jaw of which is pivotably supported on the effector and is likewise operable by means of the instrument handle.
In more concrete terms, the gear trains enable at least a first movement of the instrument handle, according to this prior art to be triggered by the rotation of an operator's hand, to be transformed into a rotation of the effector at a predetermined transmission ratio with respect to this operating movement. This makes it possible to rotate the effector despite the relatively restricted possibility of motion of a human hand about up to 300°, for instance, and, thus, to realize complex motions without changing the grip at the handle. Moreover, a second movement of the instrument handle, for instance bending the same with respect to the tube shaft, is converted into an inclination movement of the instrument head.
The gear trains provided inside the instrument handle and the tube shaft are designed such that a most largely decoupled operation of each individual movement of the instrument head and the effector is permitted. However, such gears are necessarily extremely complex and, consequently, also require sufficient assembly space. Moreover, a complete decoupling of the individual movements is not completely ensured.
In view of this prior art, it is the object of the present invention to provide a surgical instrument of this generic type in which motions of an instrument head as well as of an effector can be performed decoupled from each other via an instrument handle.